scanf-read-list accepts a format string and an optional port or string to
read from (else the current-input-port is used for input). The output
is a list of the tokens successfully read:

> (scanf-read-list "%d %d %d""1 23 456")(123456)

scanf-read-values accepts a format string and an optional port or string to
read from (else the current-input-port is used for input). The output
is a set of values for the total number of tokens, and then the individual
token values successfully read: